Area Forecast Discussion
Issued by NWS Billings, MT

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FXUS65 KBYZ 012133
AFDBYZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
333 PM MDT SUN MAY 1 2016

.SHORT TERM...VALID FOR MON AND TUE...

WARM AND DRY CONDITIONS WILL PREVAIL THROUGH THE SHORT TERM
TUESDAY. A 573-578DM HIGH WILL BUILD OVER THE NORTHERN ROCKIES
MONDAY AND TUESDAY. ALTHOUGH A NORTHERLY FLOW ALOFT WILL MOVE
ACROSS THE FORECAST AREA THIS AFTERNOON...TONIGHT AND THROUGH THE
DAY MONDAY...HEIGHTS WILL ACTUALLY BE ON THE RISE. VISIBLE
SATELLITE IS CURRENTLY SHOWING SOME SCATTERED AREAS OF CU ACROSS
OUR EASTERN COUNTIES WITH A BATCH OF HIGH CLOUDS MOVING SOUTH
ACROSS OUR CENTRAL AND WESTERN COUNTIES. THESE HIGH CLOUDS ARE
EXPECTED TO BE INTO WYOMING BY EARLY EVENING AND THE CU ARE
BEGINNING TO DISSIPATE NOW AS SUBSIDENCE MOVES IN WITH THE HIGH
PRESSURE AND ARE EXPECTED TO BE TOTALLY DISSIPATED BY SUNSET.

MONDAY & TUESDAY...MODELS BRING AN UPPER LOW AND VORT MAX SOUTH
OUT OF CANADA ACROSS THE DAKOTAS MONDAY THEN ACROSS THE CENTRAL
PLAINS MONDAY NIGHT. WE DO NOT BELIEVE THIS DISTURBANCE WILL MOVE
FURTHER WEST LIKE EARLIER MODEL RUNS HAD SHOWN AS IT WILL HAVE A
DIFFICULT TIME AS HIGH PRESSURE RIDGING BUILDS OVER CENTRAL AND
EASTERN MONTANA. HOWEVER...THE DISTURBANCE COMES CLOSE ENOUGH TO
CARTER COUNTY THAT A SLIGHT CHANCE FOR A SHOWER OR ISOLATED
THUNDERSTORM WAS ADDED INTO THE FORECAST ACROSS EASTERN CARTER
COUNTY FOR MONDAY AFTERNOON. AFTERNOON HIGHS WILL WARM ABOVE
NORMAL INTO THE 60S WITH A FEW 70 DEGREE READINGS POSSIBLE. HIGH
PRESSURE RIDGING WILL BE IN FIRM CONTROL TUESDAY BRINGING SUNNY
SKIES AND TEMPERATURES ABOVE NORMAL WITH READINGS IN THE LOWER TO
MIDDLE 70S. HOOLEY

.LONG TERM...VALID FOR WED...THU...FRI...SAT...SUN...

UPPER-LEVEL RIDGE CONTINUES TO SHIFT SLOWLY EASTWARD WEDNESDAY
AND THURSDAY. DRY WX AND WARMING TREND CONTINUE WED-THU. LATE
THURSDAY...WITH THE RIDGE BEGINNING TO BREAK DOWN A STRONGER
LEESIDE TROUGH DEVELOPS WHICH PROMOTES BETTER MIXING AND GUIDANCE
HAS SHIFTED TO THURSDAY BEING THE WARMEST DAY. MODELS DO SHOW SOME
CAPE MAINLY OVER THE HIGHER TERRAIN LATE THURSDAY AS UPPER-LEVEL
DISTURBANCES APPROACH REGION FROM SOUTHWEST OUT AHEAD OF UPPER
LOW...SO HAVE CHANCE THUNDERSTORMS THEN.

FRIDAY BEGINS A COOLING TREND WITH MOISTURE INCREASING IN
EASTERLY UPSLOPE FLOW. SHOWERS ARE POSSIBLE AS DISTURBANCES MOVE
NORTH/NORTHWESTWARD AROUND THE UPPER LOW. SOME CAPE IS AROUND
AGAIN ON FRIDAY...THIS TIME FOR THE MOUNTAINS AND LOWER
ELEVATIONS...SO THUNDERSTORMS ARE POSSIBLE. FRIDAY NIGHT...MODELS
ARE IN DECENT AGREEMENT FOR RAIN OVER MUCH OF THE AREA DUE TO
Q-VECTOR CONVERGENCE TO THE NORTHEAST OF UPPER LOW. DIFFERENCES
IN THE DETAILS OF THE UPPER LOW OVER THE ROCKIES THEN EXIST FOR
SATURDAY-SUNDAY BETWEEN THE GFS AND ECMWF. GFS TRIES TO DRY OUT
THE AREA AS RIDGING WORKS SOUTHWARD...SQUASHING MOISTURE TO THE
SOUTH...WHILE THE ECMWF BRINGS THE UPPER LOW FARTHER NORTH WITH
RAIN OVER THE AREA. GIVEN THESE DIFFERENCES...HAVE LOW CHANCE
POPS FOR NEXT WEEKEND. RMS/HOOLEY

&&

.AVIATION...

VFR AND LIGHT WINDS WILL PREVAIL TONIGHT THROUGH MONDAY.
RMS/HOOLEY

&&

.PRELIMINARY POINT TEMP/POPS...

    MON     TUE     WED     THU     FRI     SAT     SUN
-----------------------------------------------------------
BIL 040/069 044/076 049/080 051/082 052/072 047/062 045/063
    00/U    00/U    00/U    11/B    23/T    55/W    33/W
LVM 030/069 036/075 041/078 045/079 046/071 044/061 041/062
    00/U    00/U    00/U    11/B    23/T    55/W    44/W
HDN 035/068 037/075 041/082 044/084 046/074 043/064 042/065
    00/U    00/U    00/U    11/B    23/T    55/W    43/W
MLS 040/070 044/077 048/081 050/084 053/077 049/067 046/067
    00/U    00/U    00/U    00/U    22/T    33/W    33/W
4BQ 034/067 037/074 041/080 046/085 049/080 047/064 043/065
    00/U    00/U    00/U    10/U    12/T    44/W    43/W
BHK 037/068 040/074 043/077 046/082 049/078 046/065 042/064
    01/B    00/U    00/U    00/U    02/T    33/W    33/W
SHR 031/065 036/073 040/077 041/081 044/073 042/061 040/061
    00/U    00/U    00/U    11/B    23/T    44/W    43/W

&&

.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.

&&

$$
WEATHER.GOV/BILLINGS



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